New tool helps target brain tumours with pinpoint precision

Life took a turn for Andrew Stewart five years ago. First, a diagnosis of skin cancer. Then the cancer spread to three tumours in his brain.

“Just smaller than a grape, you know. And I think that’s quite large,” Andrew says of the tumours in his brain. “So my next worry was, if they are growing, are they going to press against to start giving me headaches?”

Andrew was referred to Sunnybrook, the first hospital in Canada to offer radiosurgery through a technology called the Gamma Knife Icon.

The Gamma Knife delivers focused radiation to tumours that have spread (metastasized) to a patient’s brain. The frameless Gamma Knife Icon means the patient doesn’t have to have a frame screwed into their head to keep them still while the radiation beams carefully target their brain tumours.

Patients lie on the device’s table, and are fitted with a customized mask to keep their head still during treatment. The customized Icon image-guidance system then allows for precise doses of radiation to be delivered to multiple tumours in the brain simultaneously.

This is a huge advance to delivering radiation, as opposed to whole brain radiation of the past, which can cause side effects like memory loss and fatigue. It also means patients skip the discomfort of having their head secured with screws in an invasive frame during treatment.

“For a long time, patients with brain tumours and metastases were largely considered at the end of life, and using the fanciest equipment known to man was thought to be unjustified,” says Dr. Arjun Sahgal, radiation oncologist and head of Sunnybrook’s Cancer Ablation Therapy program. “But as patients live longer, the focus is to make them live better, and using focused radiation can improve the ability for patients to maintain their memory and quality of life. We owe it to our patients to make their end of life as comfortable and as meaningful as we can, and to offer more patients radiosurgery that would have otherwise not have had access, and that’s why technology like the Gamma Knife Icon is so important.”

And for some patients, it can happen in less than one hour.

“My team and our patients used to stay late into the night in order to do treatments, and we were limited as to how many tumours we could treat due to technical difficulties and the time it took,” says Dr. Sahgal. “Now, we are able to treat patients with multiple metastases — 5, 10 or even 15 or more — with the Icon, and because it’s frameless we can break up the treatment into a few lesions a day instead of patients laying in the machine for 4 to 6 hours.”

Andrew says so far, he has had no side effects of radiosurgery, and was back to living a quality life right away.

Sunnybrook is now teaching other centres how to best use the Gamma Knife Icon, leading a North American Icon Research Group, and conducting research to push the potential of this technology even further ahead.

Life took a turn for Andrew Stewart five years ago. First, a diagnosis of skin cancer. Then the cancer spread to three tumours in his brain.

“Just smaller than a grape, you know. And I think that’s quite large,” Andrew says of the tumours in his brain. “So my next worry was, if they are growing, are they going to press against to start giving me headaches?”

Andrew was referred to Sunnybrook, the first hospital in Canada to offer radiosurgery through a technology called the Gamma Knife Icon.

The Gamma Knife delivers focused radiation to tumours that have spread (metastasized) to a patient’s brain. The frameless Gamma Knife Icon means the patient doesn’t have to have a frame screwed into their head to keep them still while the radiation beams carefully target their brain tumours.

Patients lie on the device’s table, and are fitted with a customized mask to keep their head still during treatment. The customized Icon image-guidance system then allows for precise doses of radiation to be delivered to multiple tumours in the brain simultaneously.

This is a huge advance to delivering radiation, as opposed to whole brain radiation of the past, which can cause side effects like memory loss and fatigue. It also means patients skip the discomfort of having their head secured with screws in an invasive frame during treatment.

“For a long time, patients with brain tumours and metastases were largely considered at the end of life, and using the fanciest equipment known to man was thought to be unjustified,” says Dr. Arjun Sahgal, radiation oncologist and head of Sunnybrook’s Cancer Ablation Therapy program. “But as patients live longer, the focus is to make them live better, and using focused radiation can improve the ability for patients to maintain their memory and quality of life. We owe it to our patients to make their end of life as comfortable and as meaningful as we can, and to offer more patients radiosurgery that would have otherwise not have had access, and that’s why technology like the Gamma Knife Icon is so important.”

And for some patients, it can happen in less than one hour.

“My team and our patients used to stay late into the night in order to do treatments, and we were limited as to how many tumours we could treat due to technical difficulties and the time it took,” says Dr. Sahgal. “Now, we are able to treat patients with multiple metastases — 5, 10 or even 15 or more — with the Icon, and because it’s frameless we can break up the treatment into a few lesions a day instead of patients laying in the machine for 4 to 6 hours.”

Andrew says so far, he has had no side effects of radiosurgery, and was back to living a quality life right away.

Sunnybrook is now teaching other centres how to best use the Gamma Knife Icon, leading a North American Icon Research Group, and conducting research to push the potential of this technology even further ahead.

Monica Matys works in communications at Sunnybrook Health Sciences Centre.